Preheat the oven to 140℃.
Use a food processor to blitz the biscuits to a fine crumb. If you don't have a food processor then you can put them into a sandwich bag and bash them with a rolling pin.
Melt the butter then add it to the biscuit crumbs. Mix well until it is fully combined.
Press it into the bottom of an 18 cm springform tin, pressing it up the sides too. Place it into the fridge whilst you get the filling ready.
In a mixing bowl, whisk the egg yolks until smooth, then add the condensed milk, the zest and the juice of four fresh limes, the peppermint extract and a shot of rum.
Beat it with a whisk for a minute or so until it is well combined. Then pour it into the biscuit base.
Bake it for 15 minutes.
Once baked, leave it to cool to room temperature before placing it into the fridge for a couple of hours to set.
When it is ready to serve, prepare the chantilly cream. Whip the cream and vanilla paste until it reaches soft peaks. Add the icing sugar and beat until well combined, being careful not to over whip it.
Spoon it over the top of the pie then garnish with lime zest and mint tips.
